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W. E. PRALL. GONBBNSER.

Nu. 457,791. Patented Aug. 18, 1891.

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No. 457,791. Patented Aug. 18, 1891.

UNITED STATES PATENT Ormes.V

WILLIAM EDGAR PRALL, OF WASHINGTON, DISTRICT OF COLUMBIA.

CONDENSER.

SPECIFICATION forming part of Letters Patent No. 457,791, datedAugust18, 1891.

Application filed February 4| 1891.

To all whom it may concern:

Beit known that LWILLIAM EDGAR PRALL, a resident of Washington, in theDistrict ofv Columbia, have invented certain new and useful Improvementsin Condensers; and I do hereby declare the following to bel a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it pertains to make and use the same.

The invention has relation to steam-condensers, and, though primarilyintended for Fig. 6 is a side elevation of a diagrammatic view ofapparatus including air and water tanks, engine, and condenser, part ofthe latter being broken away. Figs. 7 and 8 are sectional views ofdetails on an enlarged scale.

Let 1 indicate an engine, and 2 its valvechest placed on the lower sidethereof. This arrangement of the valve-chest is most suitable for thecombined use of compressed air and highly-heated water, as set forth inmy patent, No. 449,588, dated March 31, 1891.

3 is the exhaust-pipe.

4 indicates any convenient means of supporting a vessel 5, preferably inthe form of a shallow pan. In Fig. 3 is shown at the bot-l tom thereof asection of a part of such pan and a portion of the engine exhaust-pipe3. From the sides of this pan rise the supports or posts 6 6, preferablyintegral with the pan, but not necessarily so. These posts or uprightsare arranged in pairs, the two members of each pair being oppositelyplaced on the sides of the pan. l

3 indicates a water-discharge pipe.

The uprights above described are made to sustain a fibrous sheet orsheets in the following manner: A piece of coarse woolen clothforexample, having a width a little larger Serial No. 380,175. (No model.)

than the distance between the uprights on opposite 'sides of the pan-hasone of its ends secured in any convenient manner to the end 7 of thepan. The cloth is then arranged on the uprights in such manner that itextends between the opposite posts and from the top of said posts to alittle below their junction with the sides of the pan proper. The edgeof the cloth is folded over the posts and secured thereon by means ofother similar posts or uprights, (denoted by 9,)

manner in which these folded edges are clamped between the uprights 6and 9 is indicated in Fig. 2. The clothin Fig. 3 is represented assectioned in a plane midway between and parallel to the uprights onopposite sides of the pan, the folded edge of the fabric being indicatedby broken lines.

In Figs. 4 and 5 numeral 10 indicates a water-receptacle having an inlet3,-which may be the exhaust-pipe of an engine and an outlet 3. The tube10 has several branches 11, upon each of which are secured a series ofdomes or closed tubes l2, made of wire or perforated metal and coveredwith fibrous material, such as heavy woolen cloth.

Figs. 7 and Srepresent modifications ofthe tubes 12, in which two wallsa b of wire fabric or perforated metal are made to sustain asbestusbetween them.

In Fig. 6 is diagrammatcally represented an apparatus in which .it isproposed to use the condenser, the form of th/e latter being in thisinstance that also shown in Figs. 4 and 5. A llot-water-storage tank isdenoted by 13, and a tank for com pressed air by 14. The valve-chest 2is located at the under side of the cylinder t0 provide for easydischarge of water. 15 15 indicate check-valves, and 16 16 cocks toprovide for the simultaneous admission of air and water to the cylinder.The design of this construction is to utilize compressed air andhighly-heated water in running the engine of a car or other vehicle byexpanding the mingled air and Water in the cylnder thereofs The water isused sufficiently hot to expand into steam in the cylinder, and theexpansion ofthe air absorbs its heat, with the resulting effect of verylargely increasing the work done by the air and at the same timelubricating the engine and discharging the steam or steam and Water inacomparatively cool condition. In such apparatus it is desirable thatthe cylinder be capable of being freed promptlyfrom water, and also thatthe exhaust-steam be at all times speedily and thoroughly condensed. Forthis reason the valve-chest is placed as indicated, and a condenser usedof the general character herein set forth. In these condensers awater-receptacle is connected with an exhaust-pipe near its top andbelow the condenser proper and the water-outlet is placed as low aspracticable, the arrangement being such that steam can be admitted andwater drawn oif without noise or interference of one with the other.

From the foregoing it will be understood that the pan isvon its upperside inclosed by a textile cover arranged in folds or loops secured tothe uprights and to the upper edge of the pan.

In operation steam and air are exhausted into the pan, and rising intothe recesses or bays formed by the looped fabric the air passes outthrough its interstices, the steam accompanying it being rapidlycondensed. This rapidity of condensation is insured by the finalexpansion of the air and by the fact that the air, which has free accessto the exterior of the fabric, evaporates a part of the moisture, whichis deposited by the steam in the interstices of the fabric, therebyreducing its temperature and maintaining its efficiency as a condenser.The main part of the water of condensation is deposited in the pan andmay be discharged either at intervals or continuously and either uponthe ground or into any desired receptacle.

It is characteristic of my improvement that the condenser is providedwith an extensive surface of fibrous textile or equivalent capillarymaterial, which will permit steam and air to come in actual contact, andwill allow a substantial portion of the condensed steam to be evaporatedfrom the exterior thereof. This effect may be secured by a great varietyof open fibrous fabrics, textile, metallic, mineral, or vegetable, andby means of mechanical devices for supporting such fabrics other thanthe particular one illustrated, and the condenser can be varied in theseparticulars so long as substantially the same structure and the sameprinciples of operation are preserved. Thus the particular form of thefolds or convolutions are unessential and the sizes of the intersticesthereof, provided they permit the escape of air and prevent any materialescape of steam and have a capillary action sufficient to retain Wateruntil it is evap orated by the external air. The folds of cloth, whensuch are employed, will preferably be arranged in such manner as topromote the circulation of air on their exterior, and for this purposethey may be arranged in the direction of the motion of the car when usedthereon.

I am aware that condensers have been made of Wire-cloth, and alsothatfibrous materials have been used to aid the evaporation of water forrefrigerating purposes, and such devices are not of my invention.

It is characteristic of my improvement that it brings air and condensedsteam in contact in or upon fibrous or porous material, Whereby the airaids in the evaporation of the water of condensation in or upon the wallof the condenser, the condensation of steam being aided by theevaporation of the product of previous condensation. It also providesfor the free escape of air through the capillary passages in thematerial of the condenser, and it utilizes either the final expansion ofair from the engine or external air, or both, to

cool and condense the steam within the condenser by evaporation of-water of condensation.

Having thus described my invention, what I desire to secure by LettersPatent isl. In combination with an engine and the exhaust-port thereof,a condenser inclosed by a textile fabric or the like, and a conduitleading from said exhaust-port to the condenser and adapted to conductsteam to the interior of the same, said condenser having no free outletfor steam and its fibrous or porous wall constituting its exterior beingin free communication with air, whereby all of the steam is condensedand a part of the condensed steam is evaporated from the exterior of thecondenser to reduce its temperature, substantially as set forth.

2. In combination with a steam-engine and the exhaust-port thereof, thewater-holding IIO receptacle having a convoluted cover of textile fabricor equivalent inclosing a chamber, and a conduit leading from saidexhaust-port to the condenser and adapted to conduct steam and itsiibrous or porous wall constituting its exterior being in freecommunication with air to the interior of the same, said condenserhaving no free outlet for steam, whereby all of the steam is condensedand a part of the condensed steam is evaporatedv from the exterior ofthe condenser to reduce its temperature, substantially as set forth.

3. In combination with a steam-engine and the exhaust-port thereof, thewater-holding receptacle having oppositely-placed posts on its sides,and a brous covering secured in folds upon said posts and covering thereceptacle, substantially as set forth.

for introducing steam within the condenser,

and means for bringing air in contact with 'said Wall, substantially asset forth.

In testimony whereof I have signed this 15 specification in the presenceof two subscrlbing witnesses.

VILLIAM EDGAR PRALL.

W'itnesses:

BENJ. R. CATLIN, ARCH. M. OA'rLIN.

